• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.11a
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• pp.819-823
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• 2003

The differential equations governing the shape of displacement for the shallow parabolic arch subjected to multiple dynamic point step loads were derived and solved numerically The Runge-Kutta method was used to perform the time integrations. Hinged-hinged end constraint was considered. Based on the Budiansky-Roth criterion, the dynamic critical point step loads were calculated and the dynamic stability regions for such loads were determined by using the data of critical loads obtained in this study.

• Proceedings of the KIEE Conference
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• 1997.07e
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• pp.1727-1730
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• 1997

This paper describes the surge calculations on cable cores and sheaths when an unit step surge is applied in a cable core. It is clear that the maximum core voltage appears at the ending point and maximum sheath voltage is induced at the sending points. It appears that the smaller grounding resistance can offer results having some trends which larger core voltage appears at the end point and smaller voltage is induced at the sending point.

• Korean Journal of Optics and Photonics
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• v.6 no.4
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• pp.274-281
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• 1995

The new method of recording and reconstructing a synthetic object, which was called as scannedobject holography (SOH), was proposed and its feasibility was demonstrated theoretically and experimentally. The hologram was recorded by interfering the fixed reference beam with spherical waves emitting from a moving point source, whose trajectory determined the shape of the synthetic object to be recorded. The end face of an optical fiber and the output from a pulsed laser were utilized in order to implement a moving point source experimentally. tally.

• Structural Engineering and Mechanics
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• v.18 no.2
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• pp.195-209
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• 2004

By means of the two-dimensional basic equations of transversely isotropic magneto-electro-elastic media and the strict differential operator theorem, the general solution in the case of distinct eigenvalues is derived, in which all mechanical, electric and magnetic quantities are expressed in four harmonic displacement functions. Based on this general solution in the case of distinct eigenvalues, a series of problems is solved by the trial-and-error method, including magneto-electro-elastic rectangular beam under uniform tension, electric displacement and magnetic induction, pure shearing and pure bending, cantilever beam with point force, point charge or point current at free end, and cantilever beam subjected to uniformly distributed loads. Analytical solutions to various problems are obtained.

• Coupled systems mechanics
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• v.7 no.6
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• pp.669-690
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• 2018

This paper deals with numerical modeling of dynamic failure phenomena in rate-sensitive brittle and/or ductile materials. To this end, a two-dimensional continuum viscodamage-embedded discontinuity model, which is based on our previous work (see Do et al. 2017), is developed. More specifically, the pre-peak nonlinear and rate-sensitive hardening response of the material behavior, representing the fracture-process zone creation, is described by a rate-dependent continuum damage model. Meanwhile, an embedded displacement discontinuity model is used to formulate the post-peak response, involving the macro-crack creation accompanied by exponential softening. The numerical implementation in the context of the finite element method exploiting the second-order mid-point scheme is discussed in detail. In order to show the performance of the model several numerical examples are included.

• International Journal of Internet, Broadcasting and Communication
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• v.15 no.2
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• pp.202-209
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• 2023

This study aims to analyze the correlation between semiconductor innovation and market dominance in the mobility electric vehicle industry. To this end, the study presentsstrategiesthat provide low-price competitiveness along with high-value creation in the electric vehicle and semiconductor markets. The first change in the era of high interest rates is to overcome the crisis of survival for value. Furthermore, the study acknowledges the ongoing second wave of change as the digital technology's value continues to rise, and companies experience decreased productivity due to rising ESG labor costs. The study analyzed price competitiveness in the context of the increased adoption of electric vehicles and the integration of semiconductor prices, proving that Tesla and Samsung Semiconductor have developed technology to dominate the market, with appropriate low-cost strategies applied as the value of innovation declines.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.11a
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• pp.6-7
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• 2021

Although the development of free-form architectural technology continues, it consumes a lot of money and time due to the one-time formwork and the difficulty of maintaining quality due to manual work. To this end, in this study, a shape connection technique was proposed and verified to improve the limitations of implementing the curved surface of the existing lower multi-point press. In order to improve the accuracy of the shape, a curved surface was implemented using a silicon cap and a silicon plate. As a result of the error analysis of the shape, a small value of less than 3 mm was found. This study can implement more accurate curved surfaces than conventional technologies and produce high-quality free-form panels.

• Nonlinear Functional Analysis and Applications
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• v.29 no.1
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• pp.83-98
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• 2024

In this paper, we investigate the existence and uniqueness of solutions to a new class of integro-differential equation boundary value problems (BVPs) with ㄒ-Hilfer operator. Our problem is converted into an equivalent fixed-point problem by introducing an operator whose fixed points coincide with the solutions to the given problem. Using Banach's and Schauder's fixed point techniques, the uniqueness and existence result for the given problem are demonstrated. The stability results for solutions of the given problem are also discussed. In the end. One example is provided to demonstrate the obtained results

• Journal of the Korean Institute of Telematics and Electronics B
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• v.30B no.4
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• pp.1-10
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• 1993

In this paper, a new method of phoneme segmentation of handwritten Korean characters using the local graph pattern is proposed. At first, thinning was performed before extracting features. End-point, inflexion-point, branch-point and cross-point were extracted as features. Using these features and the angular relations between these features, local graph pattern was made. When local graph pattern is made, the of strokes is investigated on contacting point. From this process, pattern is simplified as contacting pattern of the basic form and the contacting form we must take into account can be restricted within fixed region, 4therefore phoneme segmentation not influenced by characters form and any other contact in a single character is performed as matching this local graph pattern with base patterns searched ahead. This experiments with 540 characters have been conducted. From the result of this experiment, it is shown that phoneme segmentation is independent of characters form and other contact in a single character to obtain a correct segmentation rate of 95%, manages it efficiently to reduce the time spent in lock operation when the lock.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.5 no.2
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• pp.61-67
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• 2012

In this paper, In this paper, we consider a dynamic range in the frequency converter to obtain a high conversion gain and linearity while operating area proposed to broaden the design. Super-heterodyne RF Front-End style was applied to the active mixer stage, GaAs devices were used. Circuit design easy and simple forms benefit circuit is constructed in the drain mixer, passive mixer with the operating area were compared and analyzed. The simulation results of the conversion gain of 2.4dB and 0.2dBm about a gain-compression point, and showed the dynamic range of 71.9dB, when compared with passive mixers, dynamic range of approximately 6dB improvement was identified. Measurements of an approximately 2dB conversion gain and-1.0dBm of the gain-compression point, and confirmed that the active area of 71.1dB. When compared with passive mixers, dynamic range of is reduced by approximately 8dB has been improved.